This invention relates to radial arm saws, and is particularly concerned with improved dust collection systems for such saws.
My previously issued U.S. Pat. No. 3,401,724 discloses what I believe to be the first really effective dust collecting system for use in connection with radial arm saws. My said patent discloses a flat-bottomed funnel-shaped hood positioned at the rear of the work table on or slightly above the upper surface, the wide inlet end of the hood opening towards the front of the work table and the narrow outlet end of the hood opening oppositely. The hood is horizontally pivotally connected to the radial arm saw assembly so that it can be arcuately rotated to align with the saw blade. At the time I filed the application which matured into my said patent, I believed that it was desirable to mount the funnel-shaped hood on a horizontally disposed sheet metal support having a downwardly turned lip which clamped between the rip fence and the back table of the saw assembly. The hood was mounted on this support and connected to it by a bolt and thumb screw, permitting the hood to be pivoted so as to align with the saw blade.
While the device just described proved extraordinarily effective in commercial practice, my experience over the past several years led me to discover that it also had some negative aspects. For example, I found that the saw blade could come into contact with the support member when the saw was aligned at angles to the left of 0.degree. , thereby posing a safety hazard. In addition, the thumb screw attachment of the hood to the support member allowed the center of the hood floor to bulge upward, particularly at the inlet. Some dust then escaped under the hood into the room, while other dust wedged between the hood floor and the support member, interfering with the positioning of the hood. The thumb screw also tended to stick and bind, making it somewhat difficult and inconvenient to use. Still another disadvantage was the fact that the support member extended over the table clamping device which is located at the rear of the table in some saw assemblies, thereby making table spacing and fence adjustments difficult.